C++ concepts: TrivialClock

The TrivialClock concept describes the requirements satisfied by all the clocks in the chrono library.

Requirements

For a type TC:

• The type must meet Clock requirements.
• The types TC::rep, TC::duration, and TC::time_point satisfy the requirements of EqualityComparable, LessThanComparable, DefaultConstructible, CopyConstructible, CopyAssignable, Destructible, and NumericType.
• lvalues of the types TC::rep, TC::duration, and TC::time_point are Swappable.
• The function TC::now() does not throw exceptions.
• The type TC::time_point::clock meets the TrivialClock requirements, recursively.

Usage

The following types satisfy this concept in the standard library:

• std::chrono::system_clock
• std::chrono::steady_clock
• std::chrono::high_resolution_clock
• std::experimental::filesystem::file_time_type::clock